﻿using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Web.Mvc;

namespace TY.UI.Mvc
{
    public class ImgCodeController : Controller
    {
        /// <summary>
        /// 验证码
        /// </summary>
        public ActionResult GetImgCode()
        {
            string code;
            var bf = GetImgCode(out code).GetBuffer();
            Session["ValidateCode"] = code;
            return File(bf, "Content-Type:image/png;", "imgcode.png");
        }
        /// <summary>
        /// 生成验证码
        /// </summary>
        /// <param name="chkCode"></param>
        /// <returns></returns>
        private MemoryStream GetImgCode(out string chkCode)
        {
            chkCode = string.Empty;
            //颜色列表，用于验证码、噪线、噪点 
            Color[] color = { Color.Black, Color.Red, Color.Blue, Color.Green, Color.Orange, Color.Brown, Color.Brown, Color.DarkBlue };
            //字体列表，用于验证码 
            string[] font = { "Times New Roman", "MS Mincho", "Book Antiqua", "Gungsuh", "PMingLiU", "Impact" };
            //验证码的字符集，去掉了一些容易混淆的字符 
            char[] character = { '2', '3', '4', '5', '6', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'J', 'K', 'L', 'M', 'N', 'P', 'R', 'S', 'T', 'W', 'X', 'Y' };
            Random rnd = new Random();
            //生成验证码字符串 
            for (int i = 0; i < 4; i++)
            {
                chkCode += character[rnd.Next(character.Length)];
            }
            Bitmap bmp = new Bitmap(100, 39);
            Graphics g = Graphics.FromImage(bmp);
            g.Clear(Color.White);
            //画噪线 
            //for (int i = 0; i < 10; i++)
            //{
            //    int x1 = rnd.Next(100);
            //    int y1 = rnd.Next(40);
            //    int x2 = rnd.Next(100);
            //    int y2 = rnd.Next(40);
            //    Color clr = color[rnd.Next(color.Length)];
            //    g.DrawLine(new Pen(clr), x1, y1, x2, y2);
            //}
            //画验证码字符串 
            for (int i = 0; i < chkCode.Length; i++)
            {
                string fnt = font[rnd.Next(font.Length)];
                Font ft = new Font(fnt, 18);
                Color clr = color[rnd.Next(color.Length)];
                g.DrawString(chkCode[i].ToString(), ft, new SolidBrush(clr), (float)i * 20 + 8, 8);
            }
            //画噪点 
            for (int i = 0; i < 100; i++)
            {
                int x = rnd.Next(bmp.Width);
                int y = rnd.Next(bmp.Height);
                Color clr = color[rnd.Next(color.Length)];
                bmp.SetPixel(x, y, clr);
            }
            MemoryStream ms = new MemoryStream();
            try
            {
                bmp.Save(ms, ImageFormat.Png);
            }
            finally
            {
                //显式释放资源 
                bmp.Dispose();
                g.Dispose();
            }
            return ms;
        }
    }
}